Improved lathe-dog



@une can.

J. B. weer, or en nnsndnnw YORK.

Letters Patent No. 99,269, dazed .Tamm-y 25,1870.`

IMPROVED LATHE-DOG.

The Schedule referred to in these Letters Patent and making parl: of the same.

To all whom it may concern:

Be it known that I, J. B. VEST, of Geneseo, in the county of Livingston, and "State of New York, have invented a certain new and useful `Improvement in Lathe-Dogs; and I do-hereby declare that the following is a full and exact description thereof, reference being had to the accompanying drawings, making part of this specification, in which- Figure 1 represents a side elevation of my improvenient, as connected with a bar of iron to be turned.

Figure 2, a section of the head of the dog.

Figure 3, au end view of the same.

Like letters of reference indicate corresponding parts in all the figures.

My invention consists in combining with the livecentre o1" shank of the lathe-spindle, a toothed chuck, receiving an end movement on a screw or equivalent, produced bythe forward motion of the machinery, the action being such as to dog the article being turned by simply clamping to the end, thereby avoiding the cumbersome apparatus ordinarily used, and allowing the article to be turned entire, from end to end,`at one operation, and without change.

In the drawings- V A indicates the ordinary live-centre or shank, which Y rests in the lathe-spindle, the form and construction being the same as that ordinarily used, except at the outer or'bearing-end it is cut with a screw-thread or threads, a, or provided with some equivalent arrangement that will produce the adjustment Vof the chuck Ithereon, as will be presently described.

The point b of this centre hea-rs on the bar or article to be turned in the usual manner.

Ou the end of this centre rests a chuck, B, of any desired size or form, turning freely back and forth on the screw-thread before described, or receiving endmovement in some equivalent manner.

One or both ends of this chuck are provided with a series of sharp teeth, c c c, which stand in the direcI In operation, the article to be acted upon is inserted in the 4lat-he, and the chuck B turned up '.to contact with it on screw a. Then the forward motion of the machine will tighten it in place, causing the sharppointed`teeth c o to bite into the end of the article, thereby causing it; to revolve against the resistance of the cutting-tool. Thus it will be seen that the action is automatic, and the greater` the resistance to the turning-action, the greater will be the clamping-power of the chuck. This arrangement is applicable to both metal and wood-lathes.

By this arrangement, it will be noticed that the dogging is produced at the cud of the article, and not on the sulface. Therefore, when the article is once iixed in the lat-he, it may be turned or manipulated from one end to the other, over the whole surface, without any undogging or change.

This is a very great advantage, especially in those articles where it is difficult to adjust them a second time in perfect line, on changing ends.

In ordinary lathes, the (logging at the live-end is produced by a lever-clamp, having a socket that receives the end of the article to be turned, which is held in place by a. set-screw, the lever being bent to connect with the face-plate of the lathe.

This is not o nly expensive and difficult to adjust, but, as it covers a portion of the surface of the article, the latter has to be undogged and its position reversed in the lathe, to complete the turning of the unfinished portion.

My arrangement is exceedingly cheap and simple, and occupies but little space; and, iu these respects alone, it is far superior to the dogging-devices of other lathes.

What I claim as my invention, and desire -to secure Witnesses:

R. F. Oscoop, GEO. W. MIATT. 

